Monoclonal antibodies are highly specific, sensitive reagents for identifying proteins. Knowledge about the surface antigenic structure of several types of human cancers has advanced rapidly with mouse monoclonal antibodies as serological probes, and application of these reagents to cancer diagnosis and therapy is underway. Production of human monoclonal antibodies, however, has proved more difficult to achieve. Despite much effort by many laboratories around the world, there are relatively few reports of success in the literature.
Human monoclonal antibodies which recognize cell surface and intracellular antigens derived from lymphocytes of patients with malignant melanoma have been reported (Houghton, et al, J. Exp. Med. July, 1983). Human monoclonal antibodies recognizing other cellular antigens have been made from lymphocytes of normal individuals or individuals having renal cancer, lung cancer, breast cancer or lymphoproliferative disease, (Cote, et al. Pro Nat'l. Acad. Sci. April, 1983). Other human monoclonal antibodies capable of detecting hitherto unknown cell surface and intracellular antigens have been sought.
The human monoclonal antibody producing hybridoma cell lines of the present invention were formed by fusing a mouse myeloma cell line or human lymphoblastoid cell line with human lymphocytes from normal individuals and from individuals having breast cancer, colon cancer, lung cancer, melanoma or renal cancer. The lymphocytes were obtained from peripheral blood lymphocytes from normal individuals or individuals having renal cancer, spleen cells from individuals with lymphoproliferative disease or renal cancer and tumor specimen and or lymph node specimen from lung breast, renal cancer and melanoma were also used in the fusions.
These HmAbs recognize cell surface antigens or cytoplasmic components of human cells and are useful for detecting malignant cells as well as differentiating between tissue source of malignant cells.
HmAbs recognizing cell surface antigens and cytoplasmic components are antibodies Ev248, Ch5, Ch13, Te39, Hu44, Ge1, Gr169, Sp909 and Gr431. A panel comprised of these HmAbs has been formed.
A preferred embodiment of the present invention comprises a method for distinguishing between normal and malignant human cells comprising immunoassay of the Ev248 antigenic system with the HmAb Ev248. The Ev248 antigen is found on solid tumor cell lines and is restricted to epithelial cells but is not present on solid tumors of mesenchymal or neuroectodermal origin. It is thus useful in distinguishing solid tumors of epithelial origin such as breast cancers from melanoma which is of neuroectodermal origin.
HmAb Gr169 and reacts with a cell surface antigen of various cancers; Sp909 reacts a wide cell surface antigen on a wide variety of cells; Te39, Hu44, Gr431, Ch13, Ge1 and Ch5 react with intracellular components of various cancer cells; Sp909 Ch5, Ge1 and Ch13 also react with components of normal cells. These HmAbs are useful screening agents for cancer cells. Panels have been formed for this purpose.
The assay of the present invention comprises contacting cells with the antibody recognizing cell surface antigens, or cytoplasmic components and observing the reaction between said monoclonal antibody and said antigen. In a preferred embodiment of the present invention the tissue to be assayed is first excised and is then either freshly or after being frozen or embedded in paraffin by methods well-known in the art contacted with said monoclonal antibodies. In this embodiment said antibodies may be tagged with colored groups or color forming substances such as enzymes, preferably peroxidase and its substractes, with fluorescent substances or with radioactive elements by which the location of the antibodies may be traced. Serological assay of excised tissue is also an embodiment of the present invention. Thus passive hemmaglutination, antibody inhibition assay, or glycolipid-mediated immune adherence assay may be used. Likewise and anti-humas immunoglobulin assays and Protein A assays may be employed.